• Title/Summary/Keyword: Shock fragility

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Estimation of the Allowable Bio-shock Fragility Index of Fruits for Optimum Packaging Design (적정 포장설계를 위한 과실의 바이오 허용 충격지수 추정)

  • Kim, Ghi-Seok;Jung, Hyun-Mo;Kim, Ki-Bok;Kim, Man-Soo
    • Journal of Biosystems Engineering
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    • v.32 no.6
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    • pp.416-421
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    • 2007
  • Physical damage to fruits and vegetables caused by shock degrades the value of product in the fresh market. In order to design a product/packaging system to protect the product, the G-factor to the product that causes shock damage needs to be determined. The shock fragility of organisms such as fruits with a concept correspondent to the G-factor of industrial products was calculated and we defined the allowable bio-shock fragility index as the value divided peak acceleration that was generated in safe drop height by standard acceleration of gravity. We did modeling for safe drop hight that would prevent fruits from damage by drop tests and tried to estimate the allowable bio-shock fragility index of pears and apples for optimum packaging design. The bio-shock fragility index of pears was in the range of $0.74{\sim}2.29\;G$, while apples had a slightly higher value than that of pears, of $0.51{\sim}2.98\;G$. This result shows accordance with the general fact that apples have a firmer structure and get less damage from the same impact. Based on this result, it is possible to create an optimum packaging design by providing a damage standard by impact.

In vitro Estimation of The Hounsfield Units and The Volume and Void of Canine Struvite Stones as Predictors of Fragility in Extracorporeal Shock Wave Lithotripsy

  • Wang, Ji-hwan;Hwang, Tae-sung;Jung, Dong-in;Yeon, Seong-chan;Lee, Hee-chun
    • Journal of Veterinary Clinics
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    • v.34 no.3
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    • pp.178-184
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    • 2017
  • The aim of this study was to determine whether Hounsfield units (HUs), volume, and various void parameters can predict stone fragility in extracorporeal shock wave lithotripsy (ESWL). HU, volume, porosity, number of voids/stone volume, and void distribution of 30 struvite stones were estimated using helical computed tomography (CT) and micro-CT. The number of shock waves necessary for full fragmentation was accepted as a measure of the stone fragility in ESWL. The correlations between the number of shock waves and the HU, volume, porosity, and number of voids/stone volume were examined. The number of shock waves of the two groups according to the void distribution was also compared. Stone volume correlated with the number of shock waves. Shell-patterned struvite stones were significantly less susceptible to fragmentation in ESWL than non-shell-patterned struvite stones. Stone volume and void distribution may be predictors of the outcome of ESWL treatment.

The Prediction of the Results of Drop Test Through Shock Analysis (충격해석을 통한 결과의 예측)

  • 박용석;홍성철;박철희;이우식;조항법
    • Journal of KSNVE
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    • v.4 no.3
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    • pp.345-352
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    • 1994
  • Electronic products can be subjected to many different forms of shock. These shocks are usually experienced during transporting the electronic products from a manufacturer to customers. Drop tests are performed to test the product fragility before shipment. Package cushioning materials are often used to protect electronic products from severs shock environments. In the present paper, an algorithm to predict the shock responses of the main mechanical parts is developed by use of the shock analysis in which the modal parameters extracted from vibration test are used. These results are in good agreement with the results of drop test. By use of the shock response prediction algorithm developed herein, it is possible to predict the results of drop test at various drop directions and also to select the optimal package cushioning materials.

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A Study on Osmotic Fragility of the Red Blood Cell in Histamine-treated Rabbit (Histamine에 의한 적혈구 취약성의 변화에 관한 연구)

  • Ahn, Seung-Woon;Kim, Joong-Soo;Kim, Ki-Kon;Lee, Soon-Jai
    • The Korean Journal of Physiology
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    • v.9 no.1
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    • pp.33-37
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    • 1975
  • Adult rabbits were anesthetized with nembutal, 30 mg/kg. Carotid artery and jugular vein were exposed surgically and cannulated with polyethylene tubing. Arterial blood pressure was recorded via pressure transducer on the physiograph and $100{\mu}g/ml$ of histamine solution was infused through the jugular vein by using the constant infusion pump with a rate of 0.92 ml/min or 1.40 ml/min. Mean arterial blood pressure was maintained at $40{\sim}70 mmHg$ and hypotension was kept for 2 hours. After the termination of this period, blood was taken and osmotic fragility was mea sured immediately. Also, every sample of normal blood and shocked blood was incubated for 1 hour or 2 hours at $37^{\circ}C$ in order to see whether or not there was some influence of incubation. Furthermore to clarify which component was responsible for the change on the fragility, the mixtures of normal blood cells with shocked plasma and shocked blood cells with normal plasma were also incubated at $37^{\circ}C$ for one or two hours and fragility in such cases was measured. The data obtained were analysed by probit-plot method and the concentration of saline solution at which the hemolysis started to occur, 50% of blood cells were hemolysed and that at which the red blood cells hemolysed completely were determined. The values for the blood of hypotension stage were compared with those of the control blood. The results obtained were as fellows: 1. Osmotic fragility of red blood cell was increased in hypotensive state induced by histamine. 2. The differences of osmotic fragility after two hours of incubation were negligible both in normal blood and in that of hypotensive state. 3. Osmotic resistance of normal red blood cell incubated in shock plasma was less than that of shock red blood cell incubated in normal plasma. It was suggested that plasma in hypotensive state caused by histamine might be primarily responsible for the alteration of red blood cell fragility.

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Failure-Proof Design of the PCB of a Monitor Using Deformed Mode Shape (변형 모드를 이용한 모니터용 회로 기판의 파손 저감 설계에 관한 연구)

  • Park, Sang-Hu;Lee, Bu-Yun
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.1
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    • pp.111-116
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    • 2001
  • A practical scheme to reduce failure of the PCB(Printed Circuit Board) of a monitor is introduced using deformed mode shape under mechanical shock. When the monitor is given critical shock loads, cracks are commonly initiated at the tip of a hole on the PCB. Accordingly, a deformed mode shape of the PCB is obtained using a FEM code to define a weak point on the PCB under mechanical shock, and then the position and direction of the hole is determined to prevent the failure at the critical mode shape. Also, the stress intensity factor around the weak point on the PCB is calculated to check the possibility of fracture by normal tensile stress. In conclusion, present research is useful to assist the practical design of components-layout on the PCB.

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The Effect of Heterogeneous Wage Contracts on Macroeconomic Volatility in a Financially Fragile Economy

  • Kim, Jongheuk
    • East Asian Economic Review
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    • v.21 no.2
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    • pp.167-197
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    • 2017
  • I build a small open economy (SOE) dynamic stochastic general equilibrium (DSGE) model to investigate the effect of a heterogeneous wage contract between regular and temporary workers on a macroeconomic volatility in a financially fragile economy. The imperfect financial market condition is captured by a quadratic financial adjustment cost for borrowing foreign assets, and the labor market friction is captured by a Nash bargaining process which is only available to the regular workers when they negotiate their wages with the firms while the temporary workers are given their wage which simply equals the marginal cost. As a result of impulse responsesto a domestic productivity shock, the higher elasticity of substitution between two types of workers and the lower weight on the regular workers in the firm's production process induce the higher volatilities in most variables. This is reasoned that the higher substitutability creates more volatile wage determination process while the lower share of the regular workers weakens their Nash bargaining power in the contract process.

Computational earthquake performance of plan-irregular shear wall structures subjected to different earthquake shock situations

  • Cao, Yan;Wakil, Karzan;Alyousef, Rayed;Yousif, Salim T.;Jermsittiparsert, Kittisak;Ho, Lanh Si;Alabduljabbar, Hisham;Alaskar, Abdulaziz;Alrshoudi, Fahed;Mohamed, Abdeliazim Mustafa
    • Earthquakes and Structures
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    • v.18 no.5
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    • pp.567-580
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    • 2020
  • In this paper, irregularly designed planar reinforced concrete wall structures are investigated computationally. For this purpose, structures consisting of four regular and irregular models of short-order (two-class) and intermediate (five-class) types have been investigated. The probabilistic evaluation of seismic damage of these structures has been performed by using the incremental inelastic dynamic analysis to produce the seismic fragility curve at different levels of damage. The fragility curves are based on two classes of maximum damage indices and the Jeong-Nansha three-dimensional damage index. It was found that there is a significant increase in damage probability in irregular structures compared to regular ones. The rate of increase was higher in moderate and extensive damage levels. Also, the amount of damage calculated using the two damage indices shows that the Jeong-Nensha three-dimensional damage index in these types of structures provides superior results.

Development of an integrated approach for Algerian building seismic damage assessment

  • Boukri, Mehdi;Farsi, Mohammed Naboussi;Mebarki, Ahmed;Belazougui, Mohamed
    • Structural Engineering and Mechanics
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    • v.47 no.4
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    • pp.471-493
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    • 2013
  • This paper presents a framework for seismic damage evaluation for Algerian buildings adapted from HAZUS approach (Hazard-United States). Capacity and fragility curves were adapted to fit the Algerian building typologies (Reinforced Concrete structures, Confined or Non-Confined Masonry, etc). For prediction purposes, it aims to estimate the damages and potential losses that may be generated by a given earthquake in a prone area or country. Its efficiency is validated by comparing the estimated and observed damages in Boumerd$\grave{e}$s city, in the aftermath of Boumerd$\grave{e}$s earthquake (Algeria: May $21^{st}$ 2003; $M_w$ = 6.8). For this purpose, observed damages reported for almost 3,700 buildings are compared to the theoretical predictions obtained under two distinct modelling of the seismic hazard. In one hand, the site response spectrum is built according to real accelerometric records obtained during the main shock. In the other hand, the effective Algerian seismic code response spectrum (RPA 99) in use by the time of the earthquake is considered; it required the prior fitting of Boumerd$\grave{e}$s site PGA (Peak Ground Acceleration) provided by Ambraseys' attenuation relationship.